Image processing system, image processing apparatus, image processing method

ABSTRACT

An image processing system includes an acquiring unit configured to acquire image data; a first determination unit configured to create histograms of colors in the acquired image data, and determine deemed background colors with the use of the histograms; a second determination unit configured to determine a background color based on the deemed background colors; a counting unit configured to count a number of pixels corresponding to character colors in the image data, wherein colors other than the background color are the character colors; and a deciding unit configured to obtain a ratio of the number of pixels corresponding to the character colors to a total number of pixels in the image data, and perform blank page determination on the image data by determining that the image data is blank when the ratio is less than a predetermined value.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing system, an imageprocessing apparatus, and an image processing method for performingblank page determination.

2. Description of the Related Art

Conventionally, there is a typically used method referred to as “blankpage determination” for determining whether the correct side of anoriginal has been scanned with the use of an image processing function.The blank page determination method deletes image data determined asbeing blank (i.e., image data obtained by scanning a blank page).Accordingly, this method reduces the resources used for image processing(e.g., less memory area), and also reduces processing time. Furthermore,the blank page determination method can be applied to varioustechnologies, such as dividing a document at blank pages, single-sidedscanning, double-sided scanning, improving the printing efficiency, andpage alignment (See Japanese Laid-Open Patent Application No.2008-219820 (patent document 1), or Japanese Laid-Open PatentApplication No. 2002-077669 (patent document 2)).

However, originals to be scanned include various contents. There may bea page that should not be determined as a blank page even though thereare no characters. There may be a page that should be determined as ablank page because there are no characters, but the page is notdetermined as a blank page due to patterns or noise. Thus, theconventional technology has not been capable of accurately determiningblank pages. Furthermore, the conventional technology has not beencapable of handling originals of various colors (white page, black page,colored page, inverted colors, and a page in which characters andbackground colors are combined in various ways).

-   Patent Document 1: Japanese Laid-Open Patent Application No.    2008-219820-   Patent Document 2: Japanese Laid-Open Patent Application No.    2002-077669

SUMMARY OF THE INVENTION

The present invention provides an image processing system, an imageprocessing apparatus, and an image processing method, in which one ormore of the above-described disadvantages are eliminated.

A preferred embodiment of the present invention provides an imageprocessing system, an image processing apparatus, and an imageprocessing method capable of appropriately handling various kinds ofimage data so that the blank page detection rate can be improved.

According to an aspect of the present invention, there is provided animage processing system for acquiring image data and processing theimage data, the image processing system including an acquiring unitconfigured to acquire the image data; a first determination unitconfigured to create one or more histograms of one or more colors in theimage data acquired by the acquiring unit, and determine one or moredeemed background colors with the use of the histograms; a seconddetermination unit configured to determine a background color based onthe deemed background colors determined by the first determination unit;a counting unit configured to count a number of pixels corresponding toone or more character colors in the image data, wherein colors otherthan the background color determined by the second determination unitare the character colors; and a deciding unit configured to obtain aratio of the number of pixels corresponding to the character colorscounted by the counting unit to a total number of pixels in the imagedata, and perform blank page determination on the image data bydetermining that the image data is blank when the ratio is less than afirst predetermined value.

According to an aspect of the present invention, there is provided animage processing apparatus including an acquiring unit configured toacquire image data; a first determination unit configured to create oneor more histograms of one or more colors in the image data acquired bythe acquiring unit, and determine one or more deemed background colorswith the use of the histograms; a second determination unit configuredto determine a background color based on the deemed background colorsdetermined by the first determination unit; a counting unit configuredto count a number of pixels corresponding to one or more charactercolors in the image data, wherein colors other than the background colordetermined by the second determination unit are the character colors;and a deciding unit configured to obtain a ratio of the number of pixelscorresponding to the character colors counted by the counting unit to atotal number of pixels in the image data, and perform blank pagedetermination on the image data by determining that the image data isblank when the ratio is less than a first predetermined value.

According to an aspect of the present invention, there is provided animage processing method including an acquiring step of acquiring imagedata; a first determination step of creating one or more histograms ofone or more colors in the image data acquired at the acquiring step, anddetermining one or more deemed background colors with the use of thehistograms; a second determination step of determining a backgroundcolor based on the deemed background colors determined at the firstdetermination step; a counting step of counting a number of pixelscorresponding to one or more character colors in the image data, whereincolors other than the background color determined at the seconddetermination step are the character colors; and a deciding step ofobtaining a ratio of the number of pixels corresponding to the charactercolors counted at the counting step to a total number of pixels in theimage data, and performing blank page determination on the image data bydetermining that the image data is blank when the ratio is less than afirst predetermined value.

According to one embodiment of the present invention, an imageprocessing system, an image processing apparatus, and an imageprocessing method are provided, which are capable of appropriatelyhandling various kinds of image data so that the blank page detectionrate can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings, in which:

FIG. 1 illustrates an example of an image processing system according toa first embodiment of the present invention;

FIG. 2 illustrates an example of a hardware configuration of an imageprocessing server according to the first embodiment;

FIG. 3 is a functional block diagram of an MFP and the image processingserver according to the first embodiment;

FIG. 4 is a functional block diagram of a deemed background colordetermining unit;

FIGS. 5A through 5D illustrate examples of images for which blank pagedetermination is performed;

FIGS. 6A and 6B illustrate histograms of image 1;

FIGS. 7A and 7B illustrate histograms of image 2;

FIGS. 8A and 8B illustrate histograms of image 3;

FIGS. 9A and 9B illustrate histograms of image 4;

FIG. 10 indicates experimental results 1 of blank page determinationaccording to the first embodiment;

FIGS. 11A and 11B indicate experimental results 2 of blank pagedetermination according to the first embodiment;

FIG. 12 is for describing a process concept according to the firstembodiment;

FIG. 13 is a flowchart of a blank page determination process accordingto the first embodiment;

FIG. 14 is a functional block diagram of the MFP and an image processingserver according to a second embodiment of the present invention;

FIG. 15 illustrates an example of scanning the image in units of lines;

FIG. 16 is a flowchart of a blank page determination process accordingto the second embodiment;

FIG. 17 is a functional block diagram of the MFP and an image processingserver according to a third embodiment of the present invention;

FIG. 18 is a functional block diagram of an MFP and an image processingserver according to a fourth embodiment of the present invention;

FIG. 19 illustrates examples of workflows;

FIG. 20 is a functional block diagram of a data processing unit;

FIG. 21 is a functional block diagram of the MFP and an image processingserver according to a fifth embodiment of the present invention;

FIG. 22 illustrates an example of a confirmation screen page of a blankpage detection error;

FIG. 23 is a functional block diagram of the MFP and an image processingserver according to a sixth embodiment of the present invention; and

FIG. 24 is a functional block diagram of an image processing apparatusaccording to a modification of embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description is given, with reference to the accompanying drawings, ofembodiments of the present invention.

In the following embodiments, a multifunction peripheral including aprinter function, a scanner function, a copy function, and a faxfunction installed in a single casing, is taken as an example of animage forming apparatus to which image data is input. However, thepresent invention is not sc limited, and is also applicable to any imageforming apparatus such as a scanner, a fax machine, and a copier, aslong as image data can be input.

First Embodiment System Configuration and Hardware Configuration

FIG. 1 illustrates an example of an image processing system according toa first embodiment of the present invention. As shown in FIG. 1, theimage processing system includes an MFP (Multifunction Peripheral) 10,an MFP 20, an image processing server 3C, and an information processingterminal (for example, a PC (Personal Computer), a PDA (Personal DataAssistance)) 40, which are connected via a network.

Each of the MFP 10 and the MFP 20 has a scanner function, a copyfunction, a printer function, and a fax function installed in a singlecasing. The MFP 10 and the MFP 20 generate image data by scanning apaper medium with the scanner function, and sends the generated imagedata to the image processing server 30. Details of the MFP are givenbelow.

The image processing server 30 is a computer such as a workstation forreceiving image data obtained by a scanning process of each MFP, andexecuting various processes such as a distributing process in accordancewith specified distribution settings. Distribution settings includee-mail distribution, fax distribution, and a folder distribution. Theimage processing server 30 distributes image data to an e-mail server ora file server depending on the distribution destination. The imageprocessing server 30 performs blank page determination on the acquiredimage data, and prevents needless data from being delivered or stored.

The image processing server 30 is also for executing a workflow based oninput image information, and storing or distributing a documentaccording to a workflow formulated by a user. That is, the imageprocessing server 30 also functions as an image processing apparatus asit processes an image. Details of the image processing server 30 aregiven below.

At the information processing terminal 40, a management tool pertainingto data distribution is activated by the administrator, and distributionsettings are created by sequentially selecting plug-ins for input, imageconversion, and output.

A description is given of a hardware configuration of the imageprocessing server 30 according to the first embodiment. FIG. 2illustrates an example of a hardware configuration of the imageprocessing server 30 according to the first embodiment.

As shown in FIG. 2, the image processing server 30 includes a controlunit 31, a main storage unit 32, a secondary storage unit 33, anexternal storage device I/F unit 34, a network I/F unit 36, an inputunit 37, and a display unit 38.

The control unit 31 is a CPU for controlling the respective units andfor computing and processing data. The control unit 31 is a processorfor executing programs stored in the main storage unit 32. The controlunit 31 receives data from an input device or a storage device, performscomputing and processing on the data, and outputs the data to an outputdevice or a storage device.

The main storage unit 32 may be a ROM (Read Only Memory) or a RAM(Random Access Memory), which is a storage device for storing ortemporarily holding programs executed by the control unit 31 such as theOS that is the basic software and application software, and data.

The secondary storage unit 33 may be a HDD (Hard Disk Drive), which is astorage device for storing data related to application software.

The external storage device I/F unit 34 is an interface such as a USB(Universal Serial Bus) between the image processing server 30 and astorage medium 35 (for example, a flash memory) connected to the imageprocessing server 30 via a data transmission path.

The storage medium 35 stores a predetermined program, the program storedin the storage medium 35 is installed in the image processing server 30via the external storage device I/F unit 34, and the installedpredetermined program is executable by the image processing server 30.

The network I/F unit 36 is an interface between the image processingserver 30 and peripheral devices having communications functionsconnected to the image processing server 30 via a network such as LAN(Local Area Network) or WAN (Wide Area Network) constituted by datatransmission paths such as wired and/or wireless lines.

The input unit 37 includes a keyboard including a curser key, anumerical keypad, and various functional keys, and a mouse and a slicepad for selecting a key on a display screen page of the display unit 38.The input unit 37 is a user interface for the user for giving operationinstructions to the control unit 31 or for inputting data.

The display unit 38 may be a CRT or an LCD, and displays information inaccordance with display data input from the control unit 31.

<Function Configuration>

FIG. 3 is a functional block diagram of the MFP 10 and the imageprocessing server 30. First, a description is given of the mainfunctions of the MFP 10. The MFP 10 includes an image scanning unit 101,a communications unit 102, and a distribution setting DE 103. Otherfunctions that are typically included in an MFP, such as a printerfunction, a copy function, and a fax function, are not shown.

The image scanning unit 101 scans an original with the scanning functionto acquire image data. The image data may be acquired by receiving theimage data by fax transmission or by acquiring the image data from theinformation processing terminal 40.

The communications unit 102 transmits and receives device informationand image data. Particularly, when a distribution process request or ablank page detection request for image data is received from a user, thecommunications unit 102 transmits image data and the request to theimage processing server 30.

The distribution setting DB 103 stores the plug-ins for input, imageconversion, and output, and also stores one or more workflows in whichthe respective plug-ins are combined. The distribution setting DB 103may be provided in the image processing server 30; and when thedistribution setting DB 103 is provided in the image processing server30, the MFP 10 does not need to be provided with the distributionsetting DB 103.

Next, a description is given of the main functions of the imageprocessing server 30. The image processing server 30 includes acommunications unit 301, a deemed background color determining unit 302,a background color determining unit 303, a pixel counting unit 304, ablank page determining unit 305 (deciding unit), and an image DB 306.

The communications unit 301 transmits and receives device informationand image data. Particularly, the communications unit 301 receives imagedata from the MFP 10, and sends image data that has undergone imageprocessing to a destination specified in the distribution settings.

The deemed background color determining unit 302 creates a histogram foreach color in the image data (R, G, B) acquired by the communicationsunit 301, and uses the histograms to deem the colors within apredetermined range as the deemed background colors. That is, colorsthat most frequently appear in the image data are deemed as the deemedbackground colors. Details of the deemed background color determiningunit 302 are given with reference to FIG. 4.

FIG. 4 is a functional block diagram of the deemed background colordetermining unit 302. As shown in FIG. 4, the deemed background colordetermining unit 302 includes a distribution creating unit 321, acalculating unit 322, a deeming unit 323, a selecting unit 324, and aconverting unit 325.

The distribution creating unit 321 creates a histogram for each of thecolor components (R, G, and B) of all pixels in the image data. When theimage data is in color, a histogram having 256 gradation levels iscreated for each of R, G, and B. When the image data is in grayscale,one histogram of brightness is created. Histograms are created in thisexample; however, in another example, the frequency of each gradationlevel may be counted instead.

The calculating unit 322 calculates an average x and a standarddeviation σ for each histogram created by the distribution creating unit321.

When only a single color appears in each histogram of R, G, and B, theimage data is determined to be blank (i.e., an image data obtained byscanning a blank page), and subsequent processes are not performed. Ablank page means that the color is uniform (some noise is allowable),and that the image does not include any distinctive diagrams orcharacters. It is known from experimental results that a regular blankpage has a standard deviation σ of 3 through 5. Thus, if the standarddeviation σ is greater than or equal to 10, the image data can bedetermined to be not blank. Furthermore, if the maximum value andminimum value in each histogram are the same, it means that the imagedata includes a single color. Thus, the image data is determined to beblank.

The deeming unit 323 identifies the colors within a range of plus/minusthe standard deviation σ from the average x (the standard deviation σand the average x have been calculated by the calculating unit 322), anddetermines the identified colors to be the deemed background colors.Thus, colors of high frequency in the histogram are determined to be thedeemed background colors.

In the above example, the deemed background colors are determined byidentifying colors within a range of plus/minus the standard deviation σfrom the average x. However, the deemed background colors may be thecolors ranking in the top several tens percent (predetermined value) interms of frequency.

Next, a description is given of the selecting unit 324 and theconverting unit 325; however, objects of the present invention may beachieved without the selecting unit 324 or the converting unit 325. Inthe following description, it is assumed that the selecting unit 324 andthe converting unit 325 are included.

The selecting unit 324 selects a histogram having the highest standarddeviation σ among the histograms created by the distribution creatingunit 321, and determines the selected histogram to be a representativehistogram. This selection is effective when the difference in brightnessis small between the color of the background (i.e., the sheet) and thecolors in the color image.

When a representative histogram is selected by the selecting unit 324,the deeming unit 323 determines the deemed background colors based ononly the representative histogram.

When the image data is in 4 bits or 8 bits when the distributioncreating unit 321 creates the histograms, the converting unit 325performs a “process corresponding to full-color conversion” on a paletterepresenting pixels. Specifically, the process corresponding tofull-color conversion is for creating a histogram with full-color valuesbased on palette values. It is possible to completely convert the imagedata into full-color image data; however, even without creatingfull-color image data, the histogram can be created by using full-colorvalues acquired by performing the process corresponding to full-colorconversion. Accordingly, the distribution creating unit 321 can create ahistogram for each of the color components (R, G, B), even when theimage data is in palette colors.

When creating a histogram, the distribution creating unit 321 counts theaverage values of four pixels. By smoothing the data in this manner, theimpact of noise can be mitigated. Furthermore, the distribution creatingunit 321 does not count black dots or white dots included in the imagedata. Accordingly, objects that are unlikely to be determined ascharacters can be excluded. Furthermore, the weight of the valuescounted by the distribution creating unit 321 is to be reduced towardthe edges of the image data. For example, the counted values obtainedaround the edges of the image data may be weighted by 0.2, becausecharacters are less likely to be included around the edges. Accordingly,the weight of the edge parts can be reduced.

When there are dark colors continuously arranged in a sub scanningdirection (vertical direction), the distribution creating unit 321determines such colors as scan noise. Therefore, the values counted atthese portions are multiplied by a low coefficient, so as to mitigatethe weight of scan noise caused by dust on the CCD.

The reason why the RGB color space is used for creating the histogramsis to respond to pages of various colors. If the YCrCb, YUV, or HSVcolor space was used for creating the histograms, the brightness (Y)component would have the largest deviation in most cases, and thereforethe selecting unit 324 would select the brightness histogram as therepresentative histogram. In this case, the components of chromadifference (Cr, Cb) would not be selected. Therefore, the blank pagedetermination may not be appropriately performed for color originals.

Referring back to FIG. 3, the background color determining unit 303determines the background color based on the deemed background colorsdetermined by the deemed background color determining unit 302.Specifically, the background color determining unit 303 identifies acolor within a range of plus/minus a variability z from an average y ofthe deemed background colors. The variability z is the larger valuebetween the standard deviation and a predetermined value. Thepredetermined value may be between zero and 100. Experimental resultsshow that a value of around 50 is reasonable as the predetermined value.

The pixel counting unit 304 counts the pixels having the color(s) of thecharacters (character colors), assuming that the characters are in anycolor other than the background color determined by the background colordetermining unit 303. Next, when the pixels having the character colorsare counted, the pixel counting unit 304 calculates the ratio of thenumber of pixels in character colors to the total number of pixels(hereinafter, also referred to as character appearance ratio). Thecharacter appearance ratio may be calculated by the blank pagedetermining unit 305 described below.

When the image data is long, the image data may be converted into astandard length (aspect ratio≦1.5). Specifically, when the aspect ratioof the actual length “s” of the image data exceeds an aspect ratio t(t=1.5), the character appearance ratio is multiplied by s/t, toincrease the value of the character appearance ratio. If the aspectratio was high, the area would be large, and therefore the characterappearance ratio would decrease relative to the area, which may causeerroneous determinations. The above multiplication is performed toprevent such an erroneous determination. That is, even if the ratio ofthe characters in the entire image was low, importance (weight) can beplaced on the characters.

Another method performed when the image data is long is to divide theimage data in units of A4 size sheets, and to calculate the characterappearance ratio for each section obtained by dividing the image data.Next, the largest value among the calculated character appearance ratiosis used for the blank page determination. As the character appearanceratio is obtained for each of the sections, the character appearanceratio is prevented from decreasing due to the large area.

When the ratio of characters in the entire image calculated by the pixelcounting unit 304 is less than a predetermined value, the blank pagedetermining unit 305 determines that the image data is blank. When theratio of characters in the entire image calculated by the pixel countingunit 304 is greater than or equal to the predetermined value, the blankpage determining unit 305 determines that the image data is not blank.The predetermined value may be, for example, 0.001%, 0.05%, or 0.1%,which may be changed. For example, the predetermined value may initiallybe 0.05%, and when there are many erroneous determinations, thepredetermined value may be changed to 0.001% so that the determinationsare made more precisely. When the process is actually executed with aprogram, it is time-consuming to perform computations with a numberincluding a decimal point, and therefore the predetermined value ismultiplied by a predetermined multiple (for example, 1,000,000 times),so that the blank page determination can be performed with integralnumbers.

The image DB 306 eliminates image data that is determined to be blank bythe blank page determining unit 305, and stores only image data that isnot blank.

The image processing system having the above-described configuration canappropriately respond to various kinds of image data, and can thereforeimprove the blank page detection rate.

The following is another method of determining the background color. Thedeemed background color determining unit 302 obtains the center ofgravity in a RGB three dimensional space, identifies the colors within apredetermined distance from the obtained center of gravity, anddetermines the identified colors as the deemed background colors. Next,the background color determining unit 303 obtains the center of gravityin a RGB three dimensional space based on the deemed background colors,identifies a color within a predetermined distance from the obtainedcenter of gravity, and determines the identified color as the deemedbackground color. Accordingly, a vector of the character direction withrespect to the background is obtained, and the background and thecharacters can be separated at a plane perpendicular to the vector,instead of simply separating the background and the characters in termsof distance. Accordingly, needless noise can be eliminated.

In the above example, the deemed background color determining unit 302calculates an average value to determine the deemed background colors.In another example, the deemed background color determining unit 302 mayuse a gradation level corresponding to the highest frequency (highestpeak) in the histogram instead of using an average value. In yet anotherexample, the deemed background color determining unit 302 may use amedian instead of using an average value.

<Histogram>

Next, a description is given of a histogram created by the distributioncreating unit 321, with reference to FIGS. 5A through 9. FIGS. 5Athrough 5D illustrate examples of images for which blank pagedetermination is performed. FIG. 5A illustrates an image (image 1)including colorful characters and colorful diagrams. FIG. 5B illustratesa blank image (image 2). FIG. 50 illustrates an image (image 3)including black characters. FIG. 5D illustrates a color image (image 4)without any characters or diagrams. FIGS. 6A through 6D illustratehistograms created when the images illustrated in FIGS. 5A through 9 arecolor-scanned or grayscale-scanned.

FIGS. 6A and 6B illustrate histograms of image 1. FIG. 6A illustrateshistograms of color components (R, G, B), which are created when image 1has been color-scanned. FIG. 6B illustrates a histogram created whenimage 1 has been grayscale-scanned. In the histograms shown in FIGS. 6Aand 6B, there are peaks located sporadically, which correspond to theparts where the diagrams are located.

FIGS. 7A and 7B illustrate histograms of image 2. FIG. 7A illustrateshistograms of color components (R, G, B), which are created when image 2has been color-scanned. FIG. 7B illustrates a histogram created whenimage 1 has been grayscale-scanned. As shown in FIGS. 7A and 7B, each ofthe histograms has a narrow dispersion, and has a high peak at aparticular gradation level.

FIGS. 8A and 8B illustrate histograms of image 3. FIG. 8A illustrateshistograms of color components (R, G, B), which are created when image 3has been color-scanned. FIG. 8B illustrates a histogram created whenimage 3 has been grayscale-scanned. In the histograms shown in FIGS. 8Aand 8B, there are peaks located sporadically, which correspond to theparts where the characters are located.

FIGS. 9A and 9B illustrate histograms of image 4. FIG. 9A illustrateshistograms of color components (R, G, B), which are created when image 4has been color-scanned. FIG. 9B illustrates a histogram created whenimage 4 has been grayscale-scanned. As shown in FIGS. 9A and 9B, thefrequency is counted at the gradation level corresponding to the colorof the image. In an embodiment of the present invention, the deemedbackground colors are first determined with the use of the histogramsshown in FIGS. 6A through 9B, and then the background color isdetermined from among the deemed background colors.

<Experimental Results>

FIG. 10 indicates experimental results 1 according to the firstembodiment. First, a description is given of the images used for theblank page determination.

-   Image A: blank image in light blue-   Image B: image formed by adding small characters to the center part    of image A-   Image C: blank image in gray-   Image D: blue image including characters “ASC” in slightly darker    blue than background-   Image E: image in which background and characters have the same    brightness-   Image F: image in which a character “E” is inverted-   Image G: image with red background with small characters at the top

Next, a description is given of blank page determination methodsperformed in the experiment. Present invention method: blank pagedetermination method of first embodiment described above (arepresentative histogram is selected, a predetermined value of 50 isused for determining the background color, and a predetermined value of0.05% is used for blank page determination)

Conventional technology 1 method: Ridoc Document Router (existing blankpage determination method)

Conventional technology 2 method:

-   -   (1) Specify the standard color, the deviation from standard        color, a determination threshold (%), and a peripheral part        neglect region (%) (there are stored in a parameter file) (note:        peripheral part neglect region is the peripheral part of image        to be disregarded) for example: ±128 from RGB=0x000000        (jet-black), determination threshold (%)=105%, peripheral        part=disregard 3%    -   (2) Confirm whether colors of pixels in center of image        (excluding peripheral part of image) are included among the        standard color or the colors within the deviation from the        standard color (standard color+deviation), which are specified        in (1), and count the number of pixels included in standard        color+deviation    -   (3) Calculate ratio of pixels included in standard        color+deviation to all pixels in process target    -   (4) Determine whether calculation result of (3) exceeds        determination threshold (%)

In the conventional technology 2 method, the colors can be specified;however, in this method, the sensitivity to colors is not high, and inparticular, the handling of intermediate colors is not good. Forexample, when the color of the characters and the color of thebackground are different colors but have the same brightness, thedifference in color may not be properly detected. Therefore, theinventors of the present application invention improved the conventionaltechnology 2 method by adding the following steps to solve this problem.

Improved conventional technology 2 method:

-   -   (5) Create histograms of chroma differences (Cb, Cr), and obtain        standard deviation of each histogram    -   (6) When the standard deviation of either histogram of chroma        differences (Cb, Cr) is:        -   greater than a threshold (for example, 8), the image is not            a blank page (variability of colors is high)        -   less than a threshold (for example, 8), the image is a blank            page (variability of colors is low)            Accordingly, with the improved conventional technology 2            method, the sensitivity to colors is improved compared to            the original conventional technology 2 method. However, with            the improved version of the conventional technology 2            method, errors may still occur when the area of the            characters is extremely small.

In FIG. 10, the hatched parts indicate where erroneous determinationshave been made. FIG. 10 indicates that erroneous determinations havebeen made for some images with the conventional technology 1 method, theconventional technology 2 method, and the improved conventionaltechnology 2 method. Meanwhile, with the present invention method, therewere no erroneous determinations made for any of the images, and blankpages have been properly detected. Furthermore, with respect toprocessing time, the blank page determination can be performed faster bythe present invention method than any of the conventional technology 1method, the conventional technology 2 method, and the improvedconventional technology 2 method.

FIGS. 11A and 11B indicate another experimental result. FIGS. 11A and11B indicate experimental results 2 according to the first embodiment. Adescription is given of details of the experiment of FIGS. 11A and 11B.

Images used in experiment: Double-sided scanning is performed on 20pages of originals by A4-200 dpi (half are blank)

Present invention method: blank page determination method of firstembodiment described above (a representative histogram is selected, apredetermined value of 50 is used for determining the background color,and a predetermined value of 0.05% is used for blank page determination)Conventional technology 3 method: AutoStore (NSi) Experiment conditions:Scan each page in a vertical or horizontal direction, perform blank pagedetermination by the present invention method and the conventionaltechnology 3 method, and compare the results

FIG. 11A indicates blank page determination results of the presentinvention method and the conventional technology 3 method. FIG. 11Bindicates the processing time of the present invention method and theconventional technology 3 method. As shown in FIG. 11A, with the presentinvention method, blank pages can be properly determined in bothvertical scanning and horizontal scanning. Meanwhile, with theconventional technology 3 method, erroneous determinations have beenmade in both vertical scanning and horizontal scanning. Furthermore,FIG. 11B indicates that blank page determination can be performed fasterby the present invention method than by the conventional technology 3method.

As shown in FIGS. 10, 11A, and 11B, by performing blank pagedetermination, the blank page detection rate can be improved, andprocessing time can be reduced.

<Process Concept>

Next, the process concept of the first embodiment is described withreference to FIG. 12. FIG. 12 is for describing a process conceptaccording to the first embodiment. As shown in FIG. 12, three histogramsfor RGB components are created based on the image data.

Then, among the histograms for RGB components, the histogram with thewidest dispersion (largest standard deviation σ) is selected. In theexample shown in FIG. 12, it is assumed that the histogram for R has thelargest standard deviation σ. Next, the average x and the standarddeviation σ of the histogram for R are used to determine the range ofthe deemed background colors. In the example shown in FIG. 12, the rangeof the deemed background colors is within a range of plus/minus thestandard deviation σ from the average x (180±60).

Next, the average y of the deemed background colors is calculated. Inthe example shown in FIG. 12, it is assumed that y=220. Assuming thatthe predetermined value used for determining the variability is 50, thestandard deviation σ=60 and the predetermined value 50 are compared, andthe larger value is determined to be the variability. Once thevariability is determined, the range of background color is determined.In the example shown in FIG. 12, the range of the background color isaverage y±variable (220±60). However, the maximum value is 255.

Thus, in the example shown in FIG. 12, the range of background colors is160 through 255, and the color of characters is outside the range ofbackground colors, and therefore the range of the character colors is 0through 159. The number of pixels included in this range of charactercolors is counted (or the number of pixels in the range of backgroundcolors may be counted, and the counted number may be subtracted from thetotal number of pixels), to calculate the character appearance ratio.

Finally, the character appearance ratio is compared with a predeterminedvalue (e.g., 0.05%) used for blank page determination, and when thecharacter appearance ratio exceeds the predetermined value, it isdetermined that the image is not blank.

<Operation>

FIG. 13 is a flowchart of a blank page determination process accordingto the first embodiment. As shown in FIG. 13, in step S11, thedistribution creating unit 321 creates histograms for RGB based on theacquired image data.

In step S12, the distribution creating unit 321 determines whether eachof the created histograms for RGB corresponds to a single color. This isdone by determining whether maximum value=minimum value is satisfied ineach histogram. If maximum value=minimum value is satisfied in eachhistogram, it means that the image data is in a single color. When thedetermination result in step S12 is YES (single color), the processproceeds to step S22. When the determination result in step S12 is NO(not single color), the process proceeds to step S13.

In step S13, the selecting unit 324 selects the histogram having thehighest standard deviation σ from among the three histograms for RGB. Instep S14, the calculating unit 322 calculates the average x and thestandard deviation σ of the histogram selected by the selecting unit324.

In step S15, the deeming unit 323 determines the deemed backgroundcolors (x±σ) based on the average x and the standard deviation σcalculated by the calculating unit 322.

In step S16, the background color determining unit 303 calculates theaverage y of the deemed background colors determined by the deeming unit323. In step S17, the background color determining unit 303 compares thestandard deviation σ with a predetermined value (for example, 50), anddetermines the larger value as the variability. Next, the backgroundcolor determining unit 303 identifies a color within a range ofplus/minus the variability (the determined value) from the average y,and determines the identified color as the background color. It isassumed that the minimum value is 0 and the maximum value is 255 forboth the deemed background colors and the background color.

In step S18, the pixel counting unit 304 counts the number of pixels ofcharacter colors, assuming that any color other than the backgroundcolor is a character color. The pixel counting unit 304 may count thenumber of pixels of the background color, and subtract the counted colorfrom the total number of pixels in the image to obtain the number ofpixels of character colors.

In step S19, the blank page determining unit 305 calculates the ratio ofthe number of pixels of character colors counted by the pixel countingunit 304 to the total number of pixels in the image.

In step S20, the blank page determining unit 305 determines whether thecalculated character appearance ratio is less than a predeterminedvalue. When the determination result at step S20 is YES (less thanpredetermined value), the process proceeds to step S22. When thedetermination result at step S20 is NO (greater than or equal topredetermined value), the process proceeds to step S21.

In step S21, the blank page determining unit 305 determines that theacquired image data is not blank, and ends the blank page determinationprocess. In step S22, the blank page determining unit 305 determinesthat the acquired image data is blank, and ends the blank pagedetermination process.

According to the first embodiment, it is possible to appropriatelyrespond to various kinds of image data so that the blank page detectionrate can be improved.

Second Embodiment

Next, a description is given of an image processing system according toa second embodiment of the present invention. In the second embodiment,the image data is divided, and blank page determination is performed inunits of sections formed by dividing the image data (into divisionunits), so that blank page determination can be performed at high speed.

<Function Configuration>

FIG. 14 is a functional block diagram of the MFP 10 and an imageprocessing server 50 according to the second embodiment. In FIG. 14, thesame functions as those of FIG. 3 are denoted by the same referencenumerals and are not further described.

As shown in FIG. 14, the image processing server 50 includes thecommunications unit 301, a dividing unit 501, a deemed background colordetermining unit 502, a background color determining unit 503, a pixelcounting unit 504, a blank page determining unit 505 (deciding unit),and the image DB 306.

The dividing unit 501 divides the image data acquired by thecommunications unit 301 into predetermined sections (division units).The predetermined sections may be in units of lines, or in units ofrectangular sections. In this example, the image is divided into linesand every eleventh line is read. In an embodiment of the presentinvention, the lines are preferably scanned in an irregular manner, andtherefore the number of lines is eleven, which is a reasonably largeprime number. However, it goes without saying that the present inventionis not limited to reading every eleventh line of the image data.

The deemed background color determining unit 502 sequentially reads thesections (division units) of the image data divided in units of lines bythe dividing unit 501, renews the histograms for each of the colors (R,G, B), uses the renewed histograms to identify the colors within apredetermined range, and determines the identified colors as deemedbackground colors in the sections. That is, colors that most frequentlyappear in the image data (in the division unit) are deemed as the deemedbackground colors.

The background color determining unit 503 determines the backgroundcolor based on the deemed background colors in the division unit,whereby the deemed background colors have been determined by the deemedbackground color determining unit 502. The method of determining thebackground color is the same as the first embodiment, and is thus notfurther described.

The pixel counting unit 504 counts the number of pixels having charactercolors in the division unit, assuming that any color other than thebackground color determined by the background color determining unit 503is a character color. Next, when the number of pixels of charactercolors has been counted, the pixel counting unit 504 calculates thecharacter appearance ratio, i.e., the ratio of the counted number ofpixels of character colors to the total number of pixels scanned in thefirst round of scanning the image in units of lines.

The blank page determining unit 505 determines that the image is blankwhen the character appearance ratio calculated by the pixel countingunit 504 is less than a predetermined value, and determines that theimage is not blank when the character appearance ratio is greater thanor equal to the predetermined value. Similar to the first embodiment,the predetermined value may be, for example, 0.001%, 0.05%, or 0.1%,which may be changed.

When the image is determined to be blank, the blank page determiningunit 505 instructs the deemed background color determining unit 502 toscan the next set of lines and renew the histogram. In the secondembodiment, the above described blank page determination method isrepeated until the image is determined as not blank, or until the entireimage has been scanned.

FIG. 15 illustrates an example of scanning the image in units of lines.As shown in FIG. 15, the histogram is renewed every time a division unit(section) of the image data has been scanned by reading every eleventhline. First in the first round of scanning the image, the 1st line, 12thline, 23rd line, . . . are read, and a histogram is created based on theread pixels. Next, the blank page determining unit 505 performs blankpage determination based on the created histogram. When the blank pagedetermining unit 505 determines that the division unit is blank, thesecond round of scanning the image is performed. In the second round ofscanning, the 2nd line, the 13th line, the 24th line, . . . are read,and the histogram is renewed based on the read pixels. Subsequently, theabove-described process is repeated until the image is determined as notblank, or until the entire image has been scanned.

The blank page determining unit 505 performs blank page determination bymultiplying the predetermined value used for determination by acoefficient. For example, when the image is scanned at every eleventhline, a coefficient of 10 is used for the first blank pagedetermination, a coefficient of 9 is used for the second blank pagedetermination, a coefficient of 8 is used for the third blank pagedetermination, and so forth, i.e., the coefficient is decreased by oneevery additional time the blank page determination is performed. Whenthe number of scanned pixels is small, the character appearance ratiomay be erroneously high, thereby causing incorrect determinations. Thus,when the number of scanned pixels is small, the condition fordetermining whether the data is not blank is made more stringent byusing a larger predetermined value for blank page determination. As thenumber of times of scanning increases, the number of scanned pixelsincreases, and therefore the coefficient is gradually decreased, so thatthe predetermined value used for the blank page determination graduallyapproaches the original predetermined value.

As described above, when the image data is determined as not blank at anearly stage (when the number of times of scanning is small), the blankpage determination ends. Therefore, the time required for the blank pagedetermination process may be reduced.

<Operation>

FIG. 16 is a flowchart of a blank page determination process accordingto the second embodiment. As shown in FIG. 16, in step S21, the dividingunit 501 divides the image data into lines and the deemed backgroundcolor determining unit 502 scans every eleventh line of the image data.

In step S22, the blank page determination process indicated in FIG. 13is performed on the scanned pixels. In step S23, the blank pagedetermining unit 505 determines whether the scanned pixels are blank.When the determination result at step S23 is NO (not blank), the processends. When the determination result at step S23 is YES (blank), theprocess proceeds to step S24.

In step S24, the blank page determining unit 505 determines whether theentire image data has been scanned. When the determination result atstep S24 is YES (entire image has been scanned), the process ends. Whenthe determination result at step S24 is NO (entire image has not yetbeen scanned), the process returns to step S21, and the next set oflines is scanned.

According to the second embodiment, the image data is divided and blankpage determination is sequentially performed for each of the divisionunits, and therefore the blank page determination can be performed athigh speed.

Third Embodiment

Next, a description is given of an image processing system according toa third embodiment of the present invention. In the third embodiment, aprocess of removing noise (preprocess) is performed to improve theprecision of blank page determination.

<Function Configuration>

FIG. 17 is a functional block diagram of the MFP 10 and an imageprocessing server 60 according to the third embodiment. In FIG. 17, thesame functions as those of FIG. 3 are denoted by the same referencenumerals and are not further described. As shown in FIG. 17, in thethird embodiment, a preprocess unit 601 is added to the functionalconfiguration of the first embodiment.

The preprocess unit 601 performs image processing operations on theimage data acquired by the communications unit 301, before the processof the deemed background color determining unit 302 is performed. Theimage processing operation performed by the preprocess unit 601 may be,for example, removing noise, punching holes, and removing peripheralnoise. The process of removing peripheral noise is for removing noisesuch as black streaks or shadows formed at peripheral parts of theimage, caused due to a distortion of the sheet during the scanningprocess or due to the mechanism of the scanning device.

Furthermore, when the image data is in color or grayscale, thepreprocess unit 601 may perform image processing operations such assmoothing, real time thresholding, and eliminating show-through of animage on the other side of the sheet. The image processing operationsmay be selected by the user and set in advance, or may be selected everytime the blank page determination is performed.

According to the third embodiment, preprocessing is performed accordingto the user's selection, thereby improving the precision of the blankpage determination process.

Fourth Embodiment

Next, a description is given of an image processing system according toa fourth embodiment of the present invention. In the fourth embodiment,a description is given of the process of distributing the image datathat has undergone blank page determination.

<Function Configuration>

FIG. 18 is a functional block diagram of an MFP 15 and an imageprocessing server 70 according to the fourth embodiment. In FIG. 18, thesame functions as those of FIG. 3 are denoted by the same referencenumerals and are not further described. As shown in FIG. 18, in thefourth embodiment, the MFP 15 includes a distribution setting unit 151,and the image processing server 70 includes a determining unit 701, ajob execution/management unit 702, a workflow execution unit 703, a dataprocessing unit 704, and a distribution setting DB 705.

The determining unit 701 includes the functions of the deemed backgroundcolor determining unit 302, the background color determining unit 303,the pixel counting unit 304, and the blank page determining unit 305(deciding unit), and performs blank page determination. The determiningunit 701 may not only perform the blank page determination described inthe first embodiment, but also the blank page determination described inthe second and third embodiments.

The distribution setting unit 151 of the MFP 15 displays a workflowselection screen page on an operations panel, and detects the workflowselected by the user. The distribution setting unit 151 also acquiresdistribution parameters in the workflow. The distribution parameters areacquired by causing the user to input and/or select parameters in asetting screen page. The distribution parameters are, for example, ane-mail address of the destination or setting values required for imageconversion.

The distribution setting unit 151 also detects whether a chapterdivision mode for dividing the image data into chapters has beenselected for the image data acquired by a scanning process of the imagescanning unit 101. The distribution setting unit 151 may also detectwhether the above-described blank page determination is to be performed,or the blank page determination may be set as a default setting in theimage data acquired by the scanning process. In the followingdescription, it is assumed that blank page determination is set as adefault setting.

The distribution setting unit 151 sends, to the image processing server70 via the communications unit 102, identification information of theselected workflow, distribution parameters pertaining to the workflow,and information indicating the chapter division mode if the chapterdivision mode is detected, together with the scanned image data.

A description is given of a workflow. FIG. 19 illustrates examples ofthe workflow. A workflow 1 shown in FIG. 19 performs OMR (Optical MarkRecognition). A workflow 2 performs image conversion and SMTPdistribution. A workflow 3 performs an OCR process and folderdistribution. A workflow 4 performs folder distribution and SMTPdistribution. A workflow corresponds to a distribution process that is acombination of one or more processes (plug-ins) among an input plug-in,an image conversion plug-in, and an output (distribution) plug-in.

Referring back to FIG. 18, a description is given of the imageprocessing server 70. The job execution/management unit 702 stores, inthe image DB 306, distribution parameters and image data received fromthe MFP 15 as jobs, and instructs the workflow execution unit 703 toprocess the jobs. When blank page determination has been performed onthe acquired data by the determining unit 701, the jobexecution/management unit 702 stores the image data in the image DB 306.

When a request to process the jobs has been received from the jobexecution/management unit 702, the workflow execution unit 703 controlsthe execution of the processes included in the workflow. Specifically,the workflow execution unit 703 controls the data processing unit 704 toidentify the processes of the workflow included in the job, andsequentially perform the processes included in the workflow on the imagedata acquired from the image DB 306.

When an instruction to execute the processes is received from theworkflow execution unit 703, the data processing unit 704 performs adistribution process on the image data in accordance with the receivedinstruction. That is, the data processing unit 704 sequentially executesthe processes included in the workflow in the order indicated in theworkflow, and distributes the image data to the distributiondestinations (file server, SMTP server).

The distribution setting DB 705 stores plug-ins of input, imageconversion, and output, and stores one or more workflows correspondingto a combination of the plug-ins. The distribution setting DB 705 alsostores default distribution parameters pertaining to the workflow,setting screen page information of the workflow, and setting screen pageinformation of the distribution parameters.

Next, the data processing unit 704 is described in detail with referenceto FIG. 20. FIG. 20 is a functional block diagram of the data processingunit 704. The data processing unit 704 includes an image recognitionunit 741, an image conversion unit 742, a folder distribution unit 743,an e-mail sending unit 744, and a chapter division unit 745. The unitsincluded in the data processing unit 704 may be implemented by plug-ins.

The image recognition unit 741 performs image recognition processes suchas OCR (Optical Character Recognition) and/or OMR (Optical MarkRecognition). The image conversion unit 742 performs a process ofconverting a format such as PDF, TIFF, GIF, JPEG, and JPEG2000 intoanother format. The folder distribution unit 743 performs a process ofdistributing image data to a folder of a specified server. The e-mailsending unit 744 performs an e-mail distribution process with the use ofan SMTP server.

The chapter division unit 745 divides the image data into chapters,assuming that one chapter corresponds to a section up to a point wherethe determining unit 701 determines the image to be blank, and storesthe chapters in the image DB 306. Even when the chapter division unit745 does not divide the image data into chapters, the chapter divisionunit 745 may add a chapter number to each blank page such as chapter 1,chapter 2, . . . , and store the chapters in the image DB 306.

When the job execution/management unit 702 acquires informationinstructing to perform chapter division, which is received from the MFP15, the chapter division unit 745 receives a pertinent notification. Thechapter division unit 745 that has received the notification performschapter division every time the determining unit 701 determines that theimage is blank, or when the determining unit 701 has completed theentire blank page determination process. Then, a distribution process isperformed on the image data that has undergone the blank pagedetermination process and the chapter division process.

According to the fourth embodiment, a distribution process according toa workflow can be executed on the image data that has undergone blankpage determination. That is, blank page determination can be included ina scan solution for distributing image data obtained by a scanningprocess. Furthermore, according to the fourth embodiment, the image datacan be divided into chapters, assuming that one chapter corresponds to asection up to a point where the determining unit 701 determines theimage to be blank, and the image data divided into chapters can bedistributed.

Fifth Embodiment

Next, a description is given of an image processing system according toa fifth embodiment of the present invention. In the fifth embodiment,when there are many blank pages included in the image data on which thedistribution process is to be performed, the image processing system canconfirm with a user whether to continue the distribution process.

<Function Configuration>

FIG. 21 is a functional block diagram of the MFP 15 and an imageprocessing server 75 according to the fifth embodiment. In FIG. 21, thesame functions as those of FIGS. 3 and 18 are denoted by the samereference numerals and are not further described. As shown in FIG. 21,in the fifth embodiment, the image processing server 75 includes anerror determination unit 751.

The error determination unit 751 determines that an error has occurredwhen the ratio of blank pages is greater than or equal to apredetermined value, as a result of the blank page determinationperformed by the determining unit 701. For example, when the number ofblank pages corresponds to greater than or equal to 20% of the totalnumber of pages included in the image data that has undergone the blankpage determination, the error determination unit 751 determines that anerror has occurred.

When it is determined that an error has occurred, the errordetermination unit 751 sends confirmation screen page information to theMFP 15. The confirmation screen page information may be stored in theimage DB 306 or the distribution setting DB 705.

FIG. 22 illustrates an example of the confirmation screen page of ablank page detection error. The confirmation screen page shown in FIG.22 is displayed on the operations panel of the MFP 15 when the errordetermination unit 751 determines that an error has occurred. When theMFP 15 detects that a user has pressed the “YES” button shown in FIG.22, the MFP 15 sends a pertinent report to the image processing server75, and the image processing server 75 continues the distributionprocess. When the MFP 15 detects that a user has pressed the “NO” buttonshown in FIG. 22, the MFP 15 prompts the user to instruct a scanningoperation on the image data once again.

The confirmation screen page shown in FIG. 22 only has options tocontinue the distribution process or to discontinue the distributionprocess. However, there may be an option of removing the blank pages andcontinuing the distribution process. When the user selects the processof removing the blank pages and continuing the distribution process, theworkflow execution unit 703 removes or deletes the blank pages whenacquiring the image data from the image DB 306. The subsequent processesare the same as those described in the fourth embodiment.

According to the fifth embodiment, when there are many blank pagesincluded in the image data on which the distribution process is to beperformed, the image processing system can confirm with a user whetherto continue the distribution process. Furthermore, according to thefifth embodiment, when the distribution process is continued, the blankpages can be excluded from the image data being distributed.

Sixth Embodiment

Next, a description is given of an image processing system according toa sixth embodiment of the present invention. In the sixth embodiment,image data determined as a blank page by the determining unit 701 isdeleted, and image data not determined as a blank page is distributed.

<Function Configuration>

FIG. 23 is a functional block diagram of the MFP 15 and an imageprocessing server 80 according to the sixth embodiment. In FIG. 23, thesame functions as those of FIGS. 3 and 18 are denoted by the samereference numerals and are not further described. As shown in FIG. 23,in the sixth embodiment, the image processing server 80 includes a blankpage removing unit 801.

In the following, it is assumed that the distribution setting unit 151detects a blank page removing mode, includes information indicatingblank page removal in a job, and sends the job to the image processingserver 80. The blank page removing process may be a default setting, ormay be set to be executed only in a particular workflow.

When information indicating blank page removal is included in a job, thejob execution/management unit 702 sends a pertinent report to the blankpage removing unit 801, and outputs the image to the determining unit701.

The blank page removing unit 801 deletes image data that has beendetermined as a blank page by the determining unit 701. The blank pageremoving unit 801 may delete a blank page every time the determiningunit 701 determines the data as a blank page, or may delete all of theblank pages after the determining unit 701 has completed the entireblank page determination process. Accordingly, image data from whichblank pages have been removed is stored in the image DB 306. Thesubsequent processes are the same as those described in the fourthembodiment.

According to the sixth embodiment, image data determined as a blank pageby the determining unit 701 is deleted, and image data not determined asa blank page is distributed.

[Modification]

Next, a description is given of a modification of the above embodiments.In the modification, an MFP 90 includes the above-described imageprocessing server 30. In the modification, the MFP is referred to as animage processing apparatus. As shown in FIG. 24, the function forperforming blank page determination is incorporated in the imageprocessing apparatus 90.

The functions of the image processing apparatus 90 are basically thesame as those shown in FIG. 3. However, the difference is that thedeemed background color determining unit 302 performs the deemedbackground color determining process on image data obtained by thescanning process of the image scanning unit 101.

The image processing apparatus 90 according to the modification performsa blank page determination process on image data obtained by a scanningprocess, and performs a process of not saving image data that has beendetermined as a blank page, so that resources of the apparatus can beeffectively used. Any of the image processing servers according to thesecond to sixth embodiments may be incorporated in the MFP.

Furthermore, the image processing apparatus 90 according to themodification can remove blank pages from the image data obtained by thescanning process before printing out the image data. Furthermore, theimage processing apparatus 90 can perform blank sheet detection in theimage data obtained by the scanning process, divide the image data intochapters assuming that one chapter corresponds to a section up to apoint where the image data is determined to be blank, and print theimage data divided into chapters.

Each of the image processing servers according the first to sixthembodiments has a hardware configuration using a work station or atypical computer, including a control device such as a CPU, a storagedevice such as a ROM (Read Only Memory) or a RAM, an external storagedevice such as an HDD or a CD drive device, a display device, and aninput device such as a keyboard or a mouse.

An image processing program executed by the image processing serversaccording the first to sixth embodiments may be provided by beingrecorded in a computer-readable recording medium such as a CD-ROM, aflexible disk (FD), a CD-R, and a DVD (Digital Versatile Disk), as afile having an installable format or an executable format.

An image processing program executed by the image processing serversaccording the first to sixth embodiments may be stored in a computerconnected to a network such as the Internet, and may be provided bybeing downloaded via the network. An image processing program executedby the image processing servers according the first to sixth embodimentsmay be provided or distributed via the network.

An image processing program executed by the image processing serversaccording the first to sixth embodiments may be provided by beingincorporated in advance in, for example, a ROM.

An image processing program executed by the image processing serversaccording the first to sixth embodiments is constituted by modulesincluding the above units. In terms of the actual hardware, the CPU(processor) reads the image processing program from the recording mediumand executes the image processing program to load the above units in amain storage unit, so that the deemed background color determining unit,the background color determining unit, the image number count unit, andthe blank page determining unit are generated in the main storage unit.

An image processing program executed by the MFP according themodification may be provided by being incorporated in advance in, forexample, a ROM.

An image processing program executed by the MFP according themodification may be provided by being recorded in a computer-readablerecording medium such as a CD-ROM, a flexible disk (FD), a CD-R, and aDVD (Digital Versatile Disk), as a file having an installable format oran executable format.

An image processing program executed by the MFP according themodification may be stored in a computer connected to a network such asthe Internet, and may be provided by being downloaded via the network.An image processing program executed by the MFP according themodification may be provided or distributed via the network.

An image processing program executed by the MFP according themodification is constituted by modules including the above units. Interms of the actual hardware, the CPU (processor) reads the imageprocessing program from the recording medium and executes the imageprocessing program to load the above units in a main storage unit, sothat the deemed background color determining unit, the background colordetermining unit, the image number count unit, and the blank pagedetermining unit are generated in the main storage unit.

A computer-readable recording medium having recorded thereininstructions for causing a computer to execute an image processingmethod including

an acquiring step of acquiring image data;

a first determination step of creating one or more histograms of one ormore colors in the image data acquired at the acquiring step, anddetermining on or more deemed background colors with the use of thehistograms;

a second determination step of determining a background color based onthe deemed background colors determined at the first determination step;

a counting step of counting a number of pixels corresponding to one ormore character colors in the image data, wherein colors other than thebackground color determined at the second determination step are thecharacter colors; and

a deciding step of obtaining a ratio of the number of pixelscorresponding to the character colors counted at the counting step to atotal number of pixels in the image data, and performing blank pagedetermination on the image data by determining that the image data isblank when the ratio is less than a first predetermined value.

The present invention is not limited to the specifically disclosedembodiment, and variations and modifications may be made withoutdeparting from the scope of the present invention.

The present application is based on Japanese Priority Patent ApplicationNo. 2009-010340, filed on Jan. 20, 2009 and Japanese Priority PatentApplication No. 2009-252187, filed on Nov. 2, 2009, the entire contentsof which are hereby incorporated herein by reference.

1. An image processing system for acquiring image data and processingthe image data, the image processing system comprising: an acquiringunit configured to acquire the image data; a first determination unitconfigured to create one or more histograms of one or more colors in theimage data acquired by the acquiring unit, and determine one or moredeemed background colors with the use of the histograms; a seconddetermination unit configured to determine a background color based onthe deemed background colors determined by the first determination unit;a counting unit configured to count a number of pixels corresponding toone or more character colors in the image data, wherein colors otherthan the background color determined by the second determination unitare the character colors; and a deciding unit configured to obtain aratio of the number of pixels corresponding to the character colorscounted by the counting unit to a total number of pixels in the imagedata, and perform blank page determination on the image data bydetermining that the image data is blank when the ratio is less than afirst predetermined value.
 2. The image processing system according toclaim 1, wherein the first determination unit calculates a first averagevalue and a standard deviation for each of the histograms, anddetermines colors within a range of plus/minus the standard deviationfrom the first average value as the deemed background colors.
 3. Theimage processing system according to claim 2, wherein the firstdetermination unit selects a histogram having a largest standarddeviation from among the histograms of the colors, and determines thedeemed background colors with the use of the selected histogram.
 4. Theimage processing system according to claim 1, wherein the seconddetermination unit calculates a second average value of the deemedbackground colors, and determines a color within a predetermined rangefrom the second average value as the background color.
 5. The imageprocessing system according to claim 4, wherein the second determinationunit determines a larger value between the standard deviation and asecond predetermined value as a variability value, and determines acolor within a range of plus/minus the variability value from the secondaverage value as the background color.
 6. The image processing systemaccording to claim 1, further comprising: a dividing unit configured todivide the image data into division units, wherein the image data isdivided in units of at least one of lines and regions, wherein the firstdetermination unit sequentially reads the division units of the imagedata divided by the dividing unit and renews the histograms of thecolors accordingly, and the deciding unit sequentially performs theblank page determination on the division units by multiplying the firstpredetermined value by a coefficient, and reduces the coefficient everytime a result of the blank page determination is blank.
 7. The imageprocessing system according to claim 6, wherein when the result of theblank page determination is not blank, the deciding unit refrains frominstructing the first determination unit to read a subsequent one of thedivision units of the image data, and ends the blank page determination.8. The image processing system according to claim 1, further comprising:a preprocess unit configured to perform one or more preprocessingoperations on the image data, wherein the preprocessing operationsinclude removing noise, punching holes, removing at least one of aheader and a footer, eliminating show-through, and removing peripheralnoise, wherein the first determination unit creates the histograms ofthe colors in the image data that has undergone the preprocessingoperations performed by the preprocess unit.
 9. The image processingsystem according to claim 1, wherein the first determination unitcreates the histograms of the colors by performing a processcorresponding to full-color conversion, when the image data is inpalette colors.
 10. The image processing system according to claim 1,further comprising: a storing unit configured to store one or moreworkflows defining one or more processes including at least adistribution process; and a distributing unit configured to perform, onthe image data that has undergone the blank page determination performedby the deciding unit, the distribution process defined by the workflows.11. The image processing system according to claim 10, furthercomprising: a chapter division unit configured to divide the image datainto chapters, wherein each chapter corresponds to a section up to apoint where a result of the blank page determination performed by thedeciding unit is blank, wherein the distributing unit performs, on theimage data that has been divided into the chapters by the chapterdivision unit, the distribution process defined by the workflow.
 12. Animage processing apparatus comprising: an acquiring unit configured toacquire image data; a first determination unit configured to create oneor more histograms of one or more colors in the image data acquired bythe acquiring unit, and determine one or more deemed background colorswith the use of the histograms; a second determination unit configuredto determine a background color based on the deemed background colorsdetermined by the first determination unit; a counting unit configuredto count a number of pixels corresponding to one or more charactercolors in the image data, wherein colors other than the background colordetermined by the second determination unit are the character colors;and a deciding unit configured to obtain a ratio of the number of pixelscorresponding to the character colors counted by the counting unit to atotal number of pixels in the image data, and perform blank pagedetermination on the image data by determining that the image data isblank when the ratio is less than a first predetermined value.
 13. Animage processing method comprising: an acquiring step of acquiring imagedata; a first determination step of creating one or more histograms ofone or more colors in the image data acquired at the acquiring step, anddetermining one or more deemed background colors with the use of thehistograms; a second determination step of determining a backgroundcolor based on the deemed background colors determined at the firstdetermination step; a counting step of counting a number of pixelscorresponding to one or more character colors in the image data, whereincolors other than the background color determined at the seconddetermination step are the character colors; and a deciding step ofobtaining a ratio of the number of pixels corresponding to the charactercolors counted at the counting step to a total number of pixels in theimage data, and performing blank page determination on the image data bydetermining that the image data is blank when the ratio is less than afirst predetermined value.